Elastic tie plate anchor spike



1944- F. M. GRAHAM ET AL 5 ELASTIC TIE PLATE ANCHOR SPIKE Filed June 1'7, 1945 6 FZGL 1 r/l fl VA r INVENTORS:

M TMEYS.

Patented Dec. 19, 1944 ELASTIC TIE PLATE ANCHOR SPIKE Frederick M. Graham, South Whitley, Ind., and Edgar E. Martin, Altoona, Pa.

Application June 17, 1943, Serial No. 491,150

1 Claim.

The present invention relates to elastic spikes intended primarily to act as tie plate anchor spikes, although they may also be used as rail holding spikes.

The invention aims primarily to provide a spike of the elastic type which will largely eliminate wear in the top surface of the tie as caused by horizontal movements of the tie plate with respect thereto. These movements as permitted by ordinary tie plate securing spikes cause the under surface of the tie plate to rub against the top surface of the tie with the result that the tie plate gradually digs its way into the tie, forming a recess in the tie which is somewhat larger than the plate. The downward pressure of the rail spikes is thereupon lessened or entirely released, the rail supporting plates thus becoming loose and inaccurately positioned, resulting in increased wear on all the parts and allowing the rails to shift out of proper position both as to level and gauge, and producing cumulative deterioration and increased maintenance costs in the track structure as a whole. The primary object of the present invention accordingly is to provide a spike of the elastic type which will efiectively suppress the above movements and hold the tie plate securely in proper position with respect to the tie.

The invention also aims to provide a spike of the above character which is so constructed that the lateral compression forces imposed by the tie hole on the shank of the spike will not relieve or loosen up the tight engagement or pressure of the spike against the walls of the tie plate hole, the spike of the present invention being constructedto insure that high lateral pressure of the spike against the walls of the tie plate hole will be imposed or maintained under operating conditions, and without requiring special shaping operations in preboring the tie hole, and without requiring a loose fit between the spike shank and any portions of the tie hole.

It is highly desirable that a spike of the above type be capable of use with ties having pre-bored spike holes in order to avoid the destruction of the wood fibre which occurs when spikes are driven without pre-boring. portant that the spikes be capable of functioning satisfactorily in plain cylindrical spike holes, the formation of specially shaped spike holes being very expensive and also impractical for other reasons. It is also an object of the invention to provide a spike which will fulfill the above mentioned practical requirements in respect to the type of spike hole required, and to portions of the shank. As shown the upper And it is also im- 7 produce lateral stability of the spike by maintaining tight engagement of the spike shank with the wall of the spike hole throughout the length of the spike shank and particularly at the upper portion of the tie where the lateral stresses are accentuated.

Further objects and advantages of the invention will be in part obvious and in part specifically referred to in the description hereinafter contained which, taken in conjunction with the accompanying drawings, discloses a spike constructed to operate in accordance with the invention. considered merely as illustrative of the invention in its broader aspects. In the drawing- Fig. 1 is a plan view of a portion of a railroad tie and tie plate, and showing spikes constructed to operate in accordance with the invention in operative position.

Fig. 2 is a section on the plane designated by staggered angle arrows IIII in Fig. 1.

Fig. 3 is a fragmentary sectional view exemplifying the spike of this invention in an intermediate stage of the driving operation.

Fig. 4 is a transverse section on the plane indicated by the angled arrows IVIV in Fig. 2; and

Fig. 5 is a perspective view of the improved spike.

The drawing shows an ordinary wooden railroad tie 6 supporting a conventional metal tieplate I upon which a rail 8 will be seated as indicated by the dotted lines in Figs. 2 and 3. The rectangular holes 9 in the tie plate may receive rail spikes (not illustrated) of any ordinary or desired special construction to hold the rail 8 in place, and other rectangular holes I0 in the tie plate may receive spikes constructed in accordance with this invention, as indicated in general by numeral ll.

Each spike II is preferably-made of a metal bar of oblong cross section which is bent upon itself at the bottom end l2 of the spike to provide a two-part shank l3 which is of rectangular section, and appropriate to be driven into a prebored cylindrical hole I! in the tie as indicated in Figs. 2 and 3. The upper portions 15 of the shank members I3, i. e. the portions of the shank which are enclosed by the walls of the tie plate hole In when the spike is fully driven into operative position, are shaped so as to be transversely spaced from each other by a gap l6, and to provide an overall cross sectional area which is relatively large as compared to lower Such spike however should be spaced shank portions l5 are located just above wedge-like portions Ilia (see Figs. 3 and 5) which converge downwardly preferably quite abruptly to the lower shank portions l5b (Fig. 5) which are in contact with each other and thus of substantially smaller overall thickness or cross section than the upper shank portions l5. At their upper ends the portions l5 of the shank may also merge into resilient head portions H which are in contact with each other and constructed substantially as shown in Ruping Patent No. 2,015,194 issued September 24, 1935.

Fig. 3 shows the spike in partially driven position with the uppershank portions 15 disposed just above the hole III which is ultimately to receive them. The natural over-all thickness or cross section of these upper shank portions is reater than the width of hole ID, as indicated in Fig. 3, and the tapering wedge-like portions Ilia are in contact with the upper edges of hole It. Thus as the spike is further driven into fully seated position, these wedge-like portions l5a will be forced into hole i and the spaced portions I will be more and more compressed toward each other by the opposite enclosing walls of hole [0 between which they engage, thus exerting more and more resilient pressure between the shank portions l5 and such walls, until the spike finally becomes fully seated as shown in Fig. 2. Under these conditions it will be noted that the enlarged upper portions l5 of the shank may extend somewhat down into the tie 6. The shank portions lie and l5b will normally be in tight engagement with the enclosing walls of the tie hole at all points.

It should be noted that the spike is provided with what may be called bearing points I50 and l5d (see Fig. 2) which are respectively above and below the spaced portions I 5. The two legs of the spike are in contact at these points when the shank is free of lateral compression with the result that when the portions l5 of the spike are forced in the tie plate hole, these contacting points I50, I541 provide exceedingly high resistance to m0vement of the portions l5 toward each other. This resistance to distortion makes it possible to maintain a very high lateral outward pressure of the portions l5 against the opposed walls of the tie plate.

Also the outer faces of the portions l5 being at all times substantially parallel to each other, both before and after distortion, distribute this outward lateral pressure uniformly and effectively over the surfaces of the walls of the tie plate'hole with which these faces engage.

No special shaping of the pre-bored cylindrical hole I! in the tie is required, since the corners of the spike shank will force their way into the wood without relieving the outward lateral pressure imposed by the portions I5 against the tie plate, and. also the portions l5a may wedge their way into the upper part of the tie hole as shown in Fig.2, so as to be in tight engagement with the tie without relieving the high lateral outward pressure of the spike on the tie plate. Tight engagement at all of the above points is essential in eliminating the wear on the tie as caused by horizontal movements of the tie plate.

In instances where more than one of the spikes is used per tie plate, one of the spikes may have its head directed longitudinally of the rail, and another directed transversely, as shown in Fig. 1, .so as to hold the tie plate effectively against both longitudinal and transverse horizontal movements.

In actual tests with tie plate I having holes 10 which are eleven-sixteenths of an inch by threequarters of an inch, and with the gap l6 having a normal width of three-sixteenths of an inch, it has been found that the average pressure in pounds which is exerted on the tie plate hole ID in the direction of its wider dimension was 4,000 lbs., and across its narrower section about 7,600 lbs. Creepage of the tie plate with respect to the tie and penetration of the tie plate into the tie is efiectively prevented, and up and down movements of the tie plate are suppressed since the downward pressure of the spike is eifectively maintained.

While the invention has been disclosed as carried out by a spike of the above described specific construction, it should be understood that changes may be made therein without departing from the invention in its broader aspects, within the scope of the appended claims.

We claim:

An elastic tie plate anchor spike of the class described, having a shank provided with two legs which are joined at the bottom portion of the shank and which when the spike is free of lateral compression, are directed parallelto each other and with their adjacent faces substantially in contact up to a point near the top of the tie hole engageable portion of the shank, said legs having portions diverging upwardly and substantially symmetrically from said point and then running substantially parallel to each other to provide spaced substantially parallel portions en gageable with opposite upper wall portions of a tie hole and also with opposite walls of a tie plate hole when the spike is in operative position, a resilient head portion at the upper end of said shank, the portions of the legs above said parallel portions converging substantially into contact with each other when the spike is free of lateral compression, said upwardly diverging portions being constructed and arranged to force apart and closely engage opposed upper portions of the walls of a plain cylindrical tie hole when the spike is driven in place and said spaced parallel portions being resiliently distortable to wedge tightly between opposite side walls of a tie plate hole with the aforesaid upper and lower contacting portions of the legs acting to maintain outward pressure of said parallel portions against opposed walls of a tie hole and a tie plate hole and thereby hold a tie plate against hori zontal movements over the upper surface of a tie when the spike is in operative position.

FREDERICK M. GRAHAM. EDGAR E. MARTIN. 

